Stuttering and running like a bitch

MMC

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After 7k happy, well-behaved miles in my company (she's done 17k total), the GS1100 has started stattering and stuttering on constant throttle openings between about 2.5k and 4k revs and running roughly for the rest of the time. Seems to be intermittent too, just to make diagnosis really fun.

I've changed the plugs, checked the air filter and just had the valve clearances done. It's been raining (just for a change), and I wondered if it could be petrol in the water?

Any ideas? Thanks!

MMC
 
MMC said:
It's been raining (just for a change), and I wondered if it could be petrol in the water?

Do me a favour Mark... next time it rains stick a gerry can full of water outside your door and see if it's full of petrol after the rain ;)


I've seen these symtoms on a GS 11 that has had a tiny stone stuck in the throttle cable cam wheel on the throttle body. The stone had bounced in there and become stuck in the groove.... I know it's a long shot but have a check, it was like trying to ride with the throttle bodies a mile out of sync.
 
Smells more like damp or correded electrics to me, I would check all the ignition and injector connectors if you haven't already.
 
St...st...st..stuttering

Diagnosing problems at a distance is difficult, but this may help you.
The plug caps and leads may be breaking down, as your bike is an 1100 but only on low miles this might not be the problem but you must eliminate things in a logical sequence. Make sure that the ignition circuit wiring is not damaged by visual inspection, check coil mountings and earthing points for same.
You could be experiencing a throttle potentiometer mal-function or injector related fault (I'm sorry but all of these so far could produce the running fault that you describe...I'm not trying to baffle you with science.. just being helpful) Water in the fuel would tend to produce the same effect as running out of fuel and then the engine picking up again, obviouslyany water in the fuel system will be detrimental to the injectors and pump etc.
At the end of the day it might be quicker but not as cheap to go to a good bike shop and get them to investigate what the fault is, you do not have to let them repair it if you think you'r capable of making the repair. BMW dealers will probably be quicker at the diagnosis but charge more unless you visit a really good bike mechanic!
You should also make sure that the tank venting system is not blocked or resticted. If you run the engine in the dark, country lane type darkness, you may be able to see any potential ignition shorts to the HT leads and caps; if you have a garage or bike shed do this test with care and plenty of ventilation. Good luck, hope this helps you to solve the problem.
 
Cables is my bet.

Check the throttle cables, mine had a kink in the link piece that goes from left to right throttle body. Check that both throttles snap back onto there end stops.


Iain.
 
Thanks for all that - and sorry about the "petrol in the water" thing. I guess your GSs don't run on water. Petrol's so extortionately expensive here in Oxfordshire that I had mine converted ;-)

I think the way forward, having checked the various leads and injectors (visually at any rate) this morning, is a visit to BVM. At least it's a decent ride over to Stroud.

Just better make sure I don't run out of water...
 
I have the same problem

Getting Blood in my Alcohol makes me stutter...

You haven't knocked or fiddled with TPS (Throttle Position Sensor) have you? I've had a similar problem, I presume its not just that Surrrrrrrrrging that most suffer from but a bit more of a problem.

Best of luck with sorting a fix mate

G.. :)
 
Hmm. Throttle position sensor? Would someone who serviced the bike have "adjusted" this? Although I changed the oil and all that malarkey myself, I didn't have time to do the valves and check the balancing, so got someone else to do it. Wonder if there's been a bit of a cock-up...

Don't like the sound of getting blood in your alcohol stream - that's a really nasty complaint, forget st-st-stuttering GSs!

MMC
 
Well, BVM have come up trumps yet again!

I gave them a call and they managed to fit the bike in this afternoon. They tried a few things (checking throttle balance, clearances and all that malarkey), and it didn't seem to be getting a whole lot better. Then the mechanic removed what looked like a relay from under the seat and - magic - she runs perfectly again. He told me it was something to do with re-setting the EMS and getting the mixture to run a little richer. Strange - don't quite see how a relay does that...

Any ideas what the "relay" is?

MMC
 
Ah - a coding plug. Will taking it out (and leaving it out) do something evil to the engine? So far, she's running better than she ever has before, but is it all likely to go bang at some point in the future??

MMC
 
there's loads of stuff on this forum on y-piece/cat code plug removal and running lean (it's the running lean (hot) bit that f&&ks yer valves i believe). do a search and become as confused as me!

pr0ne

PS although having said that, i've got a y-piece with standard can, cat code plug removed, and by all accounts (the dealer) its running richer than it would be as standard - so i think i'm ok....
 
Yessss, there seems to be a fair bit on code plugs and anything else about rough running. Mine does run a whole lot better now, without the code plug, and doesn't seem to use a great deal more fuel, perhaps a few mpg less...

All in all, a result.

Thanks for all the help, guys! Hope I can return the favour.

MMC
 
MMC the coding plug you remove from the R1100GS is a vital part of the setup.

The coding plug on the R1150GS was an after though- It was put in to lean up the mid range & thus cut down on emissions.

The point is the 1150 was designed not to have a coding plug. The 1100 was designed to have one !!!!!!!!!
:(
 
Ah. I see. Mr Proboxer, should I put it back in soonest before the whole plot goes bang? She seemed to be running so well without it. Perhaps I should just cut my losses and get a K1100LT instead ;-)

Thanks... I think!

MMC
 
Help! After reading all the stuff in the archive about this I am thorougly confused.

Which item exactly in the GS1150 fuse box is the coding plug?
 
Was there any conclusion to the problem MMC, or are you now on a different bike (& forum)? My 1100 seems to do the same stuttering at those RPMs. Although I normally end up with a few nuts and bolts left over whenever I rebuild something, it really doesn't seem quite right to just take out the coding plug. Must do something surely.

Chris
 
I thought the coding plug was only necessary if you have a Lamba sensor (which earlier 1100's don't)?
 


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